source: rtems/cpukit/include/machine/_kernel_time.h @ f49ef6b

Last change on this file since f49ef6b was f49ef6b, checked in by Sebastian Huber <sebastian.huber@…>, on 05/18/22 at 08:00:12

Add file descriptions to kernel space headers
  • Property mode set to 100644
File size: 7.4 KB
Line 
1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (C) 2016 embedded brains GmbH
5 *
6 * Copyright (c) 1982, 1986, 1993
7 *      The Regents of the University of California.  All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 *      @(#)time.h      8.5 (Berkeley) 5/4/95
34 * $FreeBSD$
35 */
36
37/**
38 * @file
39 *
40 * @brief This header file provides time definitions for the kernel space
41 *   (_KERNEL is defined before including <sys/time.h>).
42 */
43
44#if !defined(_SYS_TIME_H_) || !defined(_KERNEL)
45#error "must be included via <sys/time.h> in kernel space"
46#endif
47
48#include <machine/_timecounter.h>
49
50/* Operations on timespecs */
51#ifndef timespecclear
52#define timespecclear(tvp)      ((tvp)->tv_sec = (tvp)->tv_nsec = 0)
53#endif
54#ifndef timespecisset
55#define timespecisset(tvp)      ((tvp)->tv_sec || (tvp)->tv_nsec)
56#endif
57#ifndef timespeccmp
58#define timespeccmp(tvp, uvp, cmp)                                      \
59        (((tvp)->tv_sec == (uvp)->tv_sec) ?                             \
60            ((tvp)->tv_nsec cmp (uvp)->tv_nsec) :                       \
61            ((tvp)->tv_sec cmp (uvp)->tv_sec))
62#endif
63
64#ifndef timespecadd
65#define timespecadd(tsp, usp, vsp)                                      \
66        do {                                                            \
67                (vsp)->tv_sec = (tsp)->tv_sec + (usp)->tv_sec;          \
68                (vsp)->tv_nsec = (tsp)->tv_nsec + (usp)->tv_nsec;       \
69                if ((vsp)->tv_nsec >= 1000000000L) {                    \
70                        (vsp)->tv_sec++;                                \
71                        (vsp)->tv_nsec -= 1000000000L;                  \
72                }                                                       \
73        } while (0)
74#endif
75#ifndef timespecsub
76#define timespecsub(tsp, usp, vsp)                                      \
77        do {                                                            \
78                (vsp)->tv_sec = (tsp)->tv_sec - (usp)->tv_sec;          \
79                (vsp)->tv_nsec = (tsp)->tv_nsec - (usp)->tv_nsec;       \
80                if ((vsp)->tv_nsec < 0) {                               \
81                        (vsp)->tv_sec--;                                \
82                        (vsp)->tv_nsec += 1000000000L;                  \
83                }                                                       \
84        } while (0)
85#endif
86
87/*
88 * Simple macros to convert ticks to milliseconds
89 * or microseconds and vice-versa. The answer
90 * will always be at least 1. Note the return
91 * value is a uint32_t however we step up the
92 * operations to 64 bit to avoid any overflow/underflow
93 * problems.
94 */
95#define TICKS_2_MSEC(t) max(1, (uint32_t)(hz == 1000) ? \
96          (t) : (((uint64_t)(t) * (uint64_t)1000)/(uint64_t)hz))
97#define TICKS_2_USEC(t) max(1, (uint32_t)(hz == 1000) ? \
98          ((t) * 1000) : (((uint64_t)(t) * (uint64_t)1000000)/(uint64_t)hz))
99#define MSEC_2_TICKS(m) max(1, (uint32_t)((hz == 1000) ? \
100          (m) : ((uint64_t)(m) * (uint64_t)hz)/(uint64_t)1000))
101#define USEC_2_TICKS(u) max(1, (uint32_t)((hz == 1000) ? \
102         ((u) / 1000) : ((uint64_t)(u) * (uint64_t)hz)/(uint64_t)1000000))
103
104/* Operations on timevals. */
105
106#define timevalclear(tvp)               ((tvp)->tv_sec = (tvp)->tv_usec = 0)
107#define timevalisset(tvp)               ((tvp)->tv_sec || (tvp)->tv_usec)
108#define timevalcmp(tvp, uvp, cmp)                                       \
109        (((tvp)->tv_sec == (uvp)->tv_sec) ?                             \
110            ((tvp)->tv_usec cmp (uvp)->tv_usec) :                       \
111            ((tvp)->tv_sec cmp (uvp)->tv_sec))
112
113/* timevaladd and timevalsub are not inlined */
114
115/*
116 * Kernel to clock driver interface.
117 */
118void    inittodr(time_t base);
119void    resettodr(void);
120
121#define time_second _Timecounter_Time_second
122#define time_uptime _Timecounter_Time_uptime
123extern struct timeval boottime;
124extern struct bintime tc_tick_bt;
125extern sbintime_t tc_tick_sbt;
126extern struct bintime tick_bt;
127extern sbintime_t tick_sbt;
128extern int tc_precexp;
129extern int tc_timepercentage;
130extern struct bintime bt_timethreshold;
131extern struct bintime bt_tickthreshold;
132extern sbintime_t sbt_timethreshold;
133extern sbintime_t sbt_tickthreshold;
134
135/*
136 * Functions for looking at our clock: [get]{bin,nano,micro}[up]time()
137 *
138 * Functions without the "get" prefix returns the best timestamp
139 * we can produce in the given format.
140 *
141 * "bin"   == struct bintime  == seconds + 64 bit fraction of seconds.
142 * "nano"  == struct timespec == seconds + nanoseconds.
143 * "micro" == struct timeval  == seconds + microseconds.
144 *
145 * Functions containing "up" returns time relative to boot and
146 * should be used for calculating time intervals.
147 *
148 * Functions without "up" returns UTC time.
149 *
150 * Functions with the "get" prefix returns a less precise result
151 * much faster than the functions without "get" prefix and should
152 * be used where a precision of 1/hz seconds is acceptable or where
153 * performance is priority. (NB: "precision", _not_ "resolution" !)
154 */
155
156#define binuptime(_bt) _Timecounter_Binuptime(_bt)
157#define nanouptime(_tsp) _Timecounter_Nanouptime(_tsp)
158#define microuptime(_tvp) _Timecounter_Microuptime(_tvp)
159
160static __inline sbintime_t
161sbinuptime(void)
162{
163        struct bintime _bt;
164
165        binuptime(&_bt);
166        return (bttosbt(_bt));
167}
168
169#define bintime(_bt) _Timecounter_Bintime(_bt)
170#define nanotime(_tsp) _Timecounter_Nanotime(_tsp)
171#define microtime(_tvp) _Timecounter_Microtime(_tvp)
172
173#define getbinuptime(_bt) _Timecounter_Getbinuptime(_bt)
174#define getnanouptime(_tsp) _Timecounter_Getnanouptime(_tsp)
175#define getmicrouptime(_tvp) _Timecounter_Getmicrouptime(_tvp)
176
177static __inline sbintime_t
178getsbinuptime(void)
179{
180        struct bintime _bt;
181
182        getbinuptime(&_bt);
183        return (bttosbt(_bt));
184}
185
186#define getbintime(_bt) _Timecounter_Getbintime(_bt)
187#define getnanotime(_tsp) _Timecounter_Getnanotime(_tsp)
188#define getmicrotime(_tvp) _Timecounter_Getmicrotime(_tvp)
189
190#define getboottime(_tvp) _Timecounter_Getboottime(_tvp)
191#define getboottimebin(_bt) _Timecounter_Getboottimebin(_bt)
192
193/* Other functions */
194int     itimerdecr(struct itimerval *itp, int usec);
195int     itimerfix(struct timeval *tv);
196int     ppsratecheck(struct timeval *, int *, int);
197int     ratecheck(struct timeval *, const struct timeval *);
198void    timevaladd(struct timeval *t1, const struct timeval *t2);
199void    timevalsub(struct timeval *t1, const struct timeval *t2);
200int     tvtohz(struct timeval *tv);
201
202#define TC_DEFAULTPERC          5
203
204#define BT2FREQ(bt)                                                     \
205        (((uint64_t)0x8000000000000000 + ((bt)->frac >> 2)) /           \
206            ((bt)->frac >> 1))
207
208#define SBT2FREQ(sbt)   ((SBT_1S + ((sbt) >> 1)) / (sbt))
209
210#define FREQ2BT(freq, bt)                                               \
211{                                                                       \
212        (bt)->sec = 0;                                                  \
213        (bt)->frac = ((uint64_t)0x8000000000000000  / (freq)) << 1;     \
214}
215
216#define TIMESEL(sbt, sbt2)                                              \
217        (((sbt2) >= sbt_timethreshold) ?                                \
218            ((*(sbt) = getsbinuptime()), 1) : ((*(sbt) = sbinuptime()), 0))
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